Spire Falls At Paris' Notre Dame As Cathedral Is...

Notre Dame Cathedral, one of the world's most famous churches, erupted in flames Monday in Paris.

Video showed flames leaping through the roof and dark smoke billowing into the sky. Observers gasped as the spire fell.

Police in Paris asked people to avoid the area to facilitate the passage of emergency vehicles.

Paris Mayor Anne Hidalgo called the fire "terrible" and said firefighters are trying to control the flames.

French President Emmanuel Macron canceled an address to the nation that was planned. "Notre-Dame de Paris is in flames," he tweeted. "Emotion of an entire nation. Thinking of all Catholics and all French people. Like all our compatriots, I am sad this evening to see this part of us burn."

There was no immediate word on the cause of the blaze, but the structure has been undergoing a $6.8 million renovation project, including work on its spire.

Located on the Île de la Cité in the middle of the Seine River, the soaring Gothic structure dates to the 13th century and was completed in the 15th century.

This is a developing story. Some things that get reported by the media will later turn out to be wrong. We will focus on reports from police officials and other authorities, credible news outlets and reporters who are at the scene. We will update as the situation develops.